Rotary air compressor



Nov. 27 1923. 1,475,683

.1. o. CARREY ROTARY A IR C OMPRES S OR Filed Aug. 2. 1919 s sheets-sheet 1 Nov. 27 1923.

JOCRREY ROTARY AIR COMPRESSOR s maa-sheet z Filed Aug. 2. 1919 Nov. 27, 1923. 1,475,683

J. O. CARREY RTARY AIR COMPRESSOR Filed Aug. 2, 1919 5 Sheets-Sheet 3 Zhi/6123202 Ja/m0. kf/e ff @7 f@ `I atented Nov.y 2 7, "1923.

UNITEIS STATES PATENT omer..

JOHN o. cAnItnY, or sT. LoUIs, MIssoUnI, AssIGNn'To cAImI'rY no'r'omr ENGINE COMPANY, or s'r. LOUIS, MIssoUnI, A CORPORATION or MISSOURI.

ROTARYy AIR COMPRESSOR.

, .A'malieation/ filed August T all whom t may concern.: j

Be it known that 1,* JOHN O. CARREY, a citizen of the United States, residing at city1 of St. ouis, State of Missouri, have invented a certain new and useful Improvement lin RotaryAir Compressors,l ofwwhich the following is a full, clear, and exact description, such as will enable others skilledin the art to which it appertains to make -and use the same, reference bein had t0 the accompanying drawings, forming lpart of this specification.

My invention relates to an air compressor of the type wherein apair of rotors having intereng'agimg peripheral portions are mounted for operation within a housing,

the principal objects of my invention being' will be effective in minimizing the leakage of iuid from t-he compressor and, also, to

provide improved means for lubricating the v operating parts of the apparatus.

VViththe foregoing and4 other objects in View, my invention consists in certain novel features of construction and arrangement of parts,` hereinafter more fully described and claimed, and illustrated in the accompanying drawings, in which- Figure 1 'is a vertical section taken through /the housing of the compressor to one side of the rotors operating therein and showing in section the fluid separator associated with vthe compressor.'

-Figure 2 is a horizontal -section taken yapproximately on line 2 2 of Figure 1.

Figure 8 is a vertical section'taken approXimately on the line 3--3 of Figure 2.

Figure 4 is a horizontal section taken approximately on the line of Figure 1.

a, i919. semi no. 314,844.

Figurei is a [vertical section taken alpproximately onlinel 5 5I of "Figure 2.

Figure 6. is "a vertical section taken vthrough the center of a reducing valve that is associated with myV improved 'co n 1p1e`sso1. 4

Figure? yis an' enlarged elevational view of a portion of the driving shaft which carlries one of the rotors'of the compressor.

taken approximately on the line'lO--lO of Figure 9. l l Referring by numerals to the accompanying drawings, 10 designates the ody or casing of thecoinpressonthe same being pro-f1 -vided with a pair of cylindrical rotor chambers 11,'the latter communicating with each other at a central point and. removably secured to the ends of this body or'casing' are heads^12 and 13. 'Y The-se heads are pro-| Figure 8 is a vertical section taken apvided with journal bearings 14 for the shafts of the rotors,'said journal bearings being provided with bushings'l and the outer ends of said 'bearings-being closed byr caps 16 in which are positioned suitable packing rings or gaskets 17. Mounted for rotation' .A

in the bearings-14 are the end portions of rotor carrying shafts 18 and 19. Shaft l18 is provided with an axially disposed bore or passageway'v 20, and shaft 19. h'asformed therein an axially disposedy bore or passageway 19a. One end of shaft 19 is extended through one of the` caps 16 in order to receive a suitable driving connection, and that.- portion vof the shaft 19 that is positioned in the bearing to which the perforated cap is applied isA provided with apl'u-V rality of grooves 21, adapted to receive a liquid packing such as oil. Theouter side face of each groove is straight and disposed at right angles tothe axis of the shaft, vsuch construction assisting in providing an effective packing against outward leakage of the oil contained in said grooves. The oil contained in thesegrooves 21, in addition to providin a liquid packing for that portion of tie shaft which performs the functions of a journal, lubricates said journal within its bearing, and the supply of oil to said grooves passes from the ttom of the adjacent rotor chamber 11 through a duct 21". the latter passing through a part of the casing 10. the head 13, and thence through the bearing 14 on said head into the chamber between said bearing and the cap 16 thereupon (see Figs. 5 and 8).

Fixed in any suitable manner on the shafts 18 and 19 within the. chambers 11 are rotors 22 and 23 the peripheries of which are provided with ribs or teeth preferably of the herringbone type which intermesh and thereby form a driving connection. The rotors are slightly shorter than the length of the chambers in which they operate and such construction provides a space 24 between the head 13 and adjacent endsofthe rotors, a`

portion of this space being occupied by packing plates 25, the peripheries being provided with suitable packing members 26. The meeting edges of these packing plates are overlapped to form a leak-proof joint 27. These plates are loosely mounted on the shafts 18 and 19 and formed in their inner faces are annular grooves 28 which are concentric with the central openings which receive said shafts 18 and 19. These grooves are adapted to receive {iuid under pressure, to counteract to a certain extent', the Huid pressure exerted on the outer faces of said plates and which latter pressure maintains them in close engagement with the adjacent ends of the rotors. These plates 25 constitute a yielding packing which readily accommodates itself to the movement resulting from the expansion and contraction of the rotors.

Formed through each rotor adjacent to its periphery is an annular row of passages 29, there being preferably one passage for each rib or tooth on the rotor and extending from each of these passages-radially through the adjacent ribs or teeth to recesses 30. Formed in the outer faces of the latter, are branch passages 31 (see Fi'gures 9 and ,10).` The passages 29 and 31 and recesses 30 are adapted to contain liquid lubricantwhich fills said recesses 30 and thus provides an effective liquid packing between the outer faces of the ribs or teeth of the rotors and the inner surfaces of the Walls around the chambers 11. Further, this liquid packing or oil serves to lubricate the peripheries of the rotors while the latter are in operation.

Formed in the end face of each rotor concentric With and arranged outside the row of passages 29, is an annular groove 32, and extending therefrom partly across the ends of the teeth or ribs of the rotor are radially disposed branch grooves 33. These grooves 32 and 33 are adapted to contain liquid lu, bricant, thus providing a lubricating packing between the ends of the rotors and the head '12 and plates 25.

Formed through each rotor and leading from the spaces between two of the ribs or teeth on the periphery thereof to the axially disposed passages 19a. and 2O are radially disposed passages 34 by means of which liquid lubricant is permitted to enter the chambers within the caps on the bearings 14 and 15, thereby providing for the lubrication of said' bearings (see Figs. 2 and 8).

Formed in the top of the casing 10 and leading upwardly therethrough from the central point between the chambers 11 is a compressed Huid outlet passageway 35 and leadingtherefrom to a 'fluid separator 36 is a tubular connection 37 in which is located a suitable check valve 38 of ordinary construction. This -uid separator may be of anyl desired construction, but preferably of the, type that is provided with an air chamber 39, a separating chamber 40, the latter being provided' with inclined baie plates 41, and a liquid chamber 42, the latter being common to the chambers 39 and 41. VLeading from the .upper portion of the separating cha-mber`40 to a compressed air tank or container (not shown) is a tubular connection 43 in which is located a check valve 43. Leading from the liquid chamber 42 is a pipe 44 and leading therefrom through the lower portion of head 12 are branch pipes 45. The inner ends of these branch pipes communicate with the chambers 10 at points in the lowermost paths of travel of the adjacent ends of the passages 29 in the rotors and thus the liquid lubricant from chamber 42 is forced into' the rotor chambers 11 and into and through the passages 29 (see Fi'gure 4). l

The fluid pressure for the chamber 24 to the rear of plates 25 is supplied through a branch pipe 46 which leads from tubularconneetion 37 and said branch pipe lead- 'ing throu h the head 13 at a central point slightly a ove the horizontal plane occu- 'pied by the aXes of the shafts 18 and 19 (see igures 3 and 5). Located in this branch pipe 46 is a suitable pressure reducing valve 46, preferably of the type illustrated in Figure 6.

Formed integralv with the lower portion of casing 10 and between the lower portions of the rotor chambers 11 is a substantially triangular block 48, the apex of which terminates immediately below the point of interengagement between the teeth orribs of the rotors, and the side faces of this triangular block are curved to 'conform to the curvature of the inner faces of the rotorchambers. Formed through the casing below Ithis block is an air inlet passage 47 and leading laterally from the upper portion thereofthrough the ,lower portion of the triangular block 48 are branch passages 49 that lead into the lower portions of the rotor chambers 1.1. A tubular.' fitting provided with a check valve 50 is located in the lower Aportion of the air inlet passageway 47.

In the operation of my improved air compressor, shaft 19 s driven in-.any suitable,

. carried approximately three-fourths of the distance around the rotor chambers 1l or to the point directly below outlet passage atwhich pointthe ribs or teeth on the rotors engage with each other.

These ribs or teeth are formed so that they have a relatively close rubbing lit and consequently very little air passes downwardly between the teeth which are in engagement with each other, and as air cannot escape backwardly between the peripheries of the rotors and the inner surfaces of the chambers 11,. said air will be compressed at a. point immediately below the passage '35 and in such condition will pass upward through the outlet passageway andfrom thence through tubular connection 37, past check valve 38 therein and into the air chamber in fluid' separator 36.

The air under pressure will pass downwardly through air chamber 39, thence upwardly through the separating chamber 40 and the Abattles therein will separate' the moisture and oil from this compressed air and the latter will pass from the separator to storage tank,- or point of use, through. outlet pipe 43 that is provided with check valve 43, The pressure wthin chamber 24 behind the plates 25, and which is necessary to maintain the latter inl engagement with .the corresponding ends of the rotors, is

taken from tubular connection 37 through pipe 46, and after passing through a suitable reducing valve, preferably of the type illustrated in Figure 6, the air -at reduced pressure is taken into the chamber 24 and thus maintains the plates`25 in yielding engagement with the' ends of the rotors. Inasmuch as theplates 25 are free to move backward and forward upon the shafts 18 and 19, they constitute a floating or yielding packing and a relativelytight joint is maintained between them and the adjacent ends of the rotors even while the same are expanded or contracted under varying degrecs of temperature. .The pressureagainst ythe outer faces of the plates is balanced in proportion to the pressure yon their inner faces so as to reduce to a minimum the mechanical friction between the ends of the v-i rotors and said plates. This counterbalancg ing eiect .is obtained by the pressure 'ex- 1 erted by the air between the ribs or `teeth of the rotors and also by the pressure malntained in the annular. grooves 28 in the inv ner faces of saidplates. I

As hereinbefore stated, the meshing of the ribs or teeth at a point immediately be- I low the lower end of outlet passage 35 compresses-the Huid at this point andthe relatively small portion of fluid which passes l 'downwardly between the teeth orl ribs, due lto slight c e the apex of the triangular portion 48 of the cas'nfr 10' land exert an eX ansive forceV against the upper faces of the ribs or teeth to the sides of said triangular portion 48,

thereby assisting the rotors in their rotary movement and consequentlyV increasing the efficiency of the compressor.

The pressure of the air within the Huid separator is directed upon the body of o'Ll that is constantly accumulating in the chamber 42 and while the compressor is in operation a 'portion of-this oil will be forced through pipe 44 and from thence through branch pipes 45 into the passages 29 through the rotors and this oil passes, into the recesses 30 to pack and lubrcate the joints between the outer faces of the ribs or teeth on the rotor and the inner surfaces ofthe walls of the chambers l1 and likewiseJ this liquid Ipacking enters the annular grooves 32 and branch grooves 33 to pack the joints between the ends of the rotors and the in- A compressor of my improved construc-v tion Vis comparatively simple, comprises relatively few parts, can be operated with the expenditure of comparatively little power, 'and is Vvery effective in performing its intended functions.

It Awill be readily understood that minor changes 4in the size, form Vand construction of the various parts of my improved rotary air compressor may be-made and substituted for-those herein shown and descr'bed, without departing from the spiritv of my invention, the scope of which is set forth in the appended claims.

claim:

1. In a fluid compressor, a housing, a pair of rotors arranged foroperation therein, which rotors have interengaging peripheral portions, means for delivering air into the rotor chambers at points below the axes of the rotors,there being a compressed air outlet leading from a central point between the rotor chambers. packing plates yieldingly arranged in surface Ycontact arance therebetween, will pass'- against said rotors at one end thereof, and in Y sure from the high pressure side of the compressor to the rotor qhambers behind said plates. r

2. In a fluid compressor, a housing, bearings arranged in pairs on said housing, caps closing the outer ends of `said bearings,

rotors journaled in said bearings, said rohigh pressure outletfor maintaining fluid pressure behind said plates.

3.V In a Huid compressor, a housing provided with a pair -of rotor chambers, rotors arranged for operation in said chambers, which rotors have interengaging peripheral portions, means for admitting air at sepa- -rate points to the lower portions of said 4 o said rotors and the surfaces of the rotor rotor chambers, said points being circumferentially displaced with respectto the zone of engagement between the rotors, there being a single compressed air outlet, leading from a central point between the rotor chambers outwardly 'from the upper portion 'of the casing, and freely movable packing plates yieldingly arranged against said ro- Itors at one end thereof and packing means arranged in the peripheral faces of said plates.

4. In a Huid compressor, a housing porvided with a pair of rotorfchambers, rotors arranged for operation in said chambers, which rotors have interengaging peripheral portions, means for admitting air at sepa-'- rate points to the lower portions ofasaid rotor chambers, and at points circumferentially displaced with respect to the zone of engagement between the rotors, there being a single compressed air outlet leading from a central point between the rotor chambers outwardly from the upper portion of the casing, and said rotors being provided in theirouter faces with channels which communicate with and are supplied with liquid byv a series oflongitudinal bores annularly arranged in the respective rotors, thereby forming a liquid seal between the outer faces ranged betweenl the lower portions of the rotor chambers, rotors arranged for operation in said rotor chambers, which rotors are provided with interengaging peripheral portions, there being air inlet passages leading tothe lower portions of the rotor chambers, and there being a com ressed air outlet passage leading through 't e housin from a point between the upper portions o the rotor chambers.

6. In a fluid compressor, a housing, apair of rotors arranged for operation' therein, which rotors have interengaging peripheral portions said rotors being provided in their endspwith annular grooves and series of radial channels leading from said grooves ind designed to receive liquid and form :oncentrical and radial liquid seals, and means for delivering air into the lower portions of the chambers in which the rotors operate, there being a compressed air outlet passage leading from the rotor chain!` bers, and counterbalanced packing plates arranged against said rotors at one end thereof said packing plates having overlapping meeting edges.

In a fluid compressor, a housing, a pair of cooperating fluid compressing rotors arrangedfor operation therein, packing plates, arranged in surface contact against said rotors at one end thereof, means for delivering fluid pressure from the high pressure side of the compressor' against the outer faces of said packing plates, and said rotors being provided in their outer faces with channels which are in communication with a series of lngitudinal bores formed in the respectivel rotors for maintaining .a liquid seal between the surfaces of said rooters and the surfaces of the rotor chambers.

8. In a fluid compressor, a housing provided with a pair of rotor chambers, rotors arranged for operation within said chambers, packing plates yieldingly arranged` against said rotors'at Ione end thereof said packing plates having free peripheral engagement, and means for delivering high pressure fluid compressed by said rotors to the rotor chambers behind the packing plates therein.

9. In a fluid compressor, a housing, cooperating rotors arranged for operation therein, packing plates yieldingly arranged against said rotors at one end thereof and having free peripheral engagement with each other, packing means carried by the peripheral portions of said packing plates, and means for delivering high pressure fluid to the 'rotor-chambers behind said plates.

10. In a fluid. compressor, a housing, cooperating rotors arranged for.' operation therein, packing plates yieldingly arranged against said rotors at one end thereof and provided with annular passageways for forming 'a liquid seal between the ends of said rotors and the respective plates, packing means carried by the peripheral portions of said packing plates, meansv for jdeliverin iuid pressure to the rotor chambers behin Sfr said plates, and means for regulating the said annular grooves to form liquid packing 10 pressure of said fluid. for the ends of said rotor,- means for deliver- 11. In a fluid compressor, a housing, a roing Huid pressure behind said packing plate tor, a packing plate arranged for yielding to yieldingly hold the same against said 5 contact with the side face of said rotor, rotor, and means for regulating the fluid said packing plate being spaced from said pressure admitted behind said packing plate. 1l housing said rotor being provided at itsV In testimony whereof I hereunto aiix n1 ends with annular' grooves and series of signature,ithis 24th da of July, 1919. branch grooves extending radially fromc J HN O. CARREY. 

